开窗径向井水力减阻及水力参数优化设计

发布时间：2018-07-18 09:50

【摘要】：开窗径向水平井技术是水射流增产方式的典型应用,是开发低孔、低渗油气藏的有效手段。与常规水平井不同的是,开窗水平井使用水力破岩钻头实现破岩钻进,钻柱通常为小通径连续油管与高压软管,钻井液在管柱中流动阻力较大,大量的水力能量耗费在沿程损耗上,破岩钻头获取的水功率有限,如果仅依靠提高地面泵压的方式来增大钻头水功率,则由此带来的设备成本将大幅提高。因此,本研究提出了在钻井液中添加减阻剂来减小沿程损耗的技术思路。本研究首先建立在分析不同类型减阻剂的减阻机理基础上,以新型径向水平井技术中常用的通径8mm软管为分析对象,采用数值模拟方法,系统研究了清水与黏弹性条件下管内沿程损耗与管长、排量、黏度的关系,发现在本研究条件下,相对于清水钻井液,黏弹性条件下的沿程损耗明显减小,且当黏度为13.5cp时软管内的沿程损耗最小,在排量为60L/min时,减阻率达到最高(51.4%),为地面实验优选减阻剂提供了理论支撑。其次,依托理论分析与数值模拟成果,初步优选了四种减阻剂:聚丙烯酰胺(PAM)、聚氧化乙烯(PEO)、Gemini黏弹性季铵盐表面活性剂、极压润滑剂HY-202,在不同质量浓度与排量条件下,测试了通径8mm尼龙软管、16mm尼龙软管与通径14.6mm连续油管的沿程损耗,并与同等工况下的清水钻井液进行了对比分析,发现:加入四种减阻剂后,沿程损耗均低于清水钻井液,且表面活性剂类减阻剂Gemini黏弹性季铵盐表面活性剂在质量浓度为1.5%时,不仅减阻率最高可达64.49%,同时具有强抗剪切性能,可作为开窗水平井理想的减阻剂。最后,进行了新型径向水平井钻井水力参数的优化设计,编制了基于本研究条件下的沿程损耗计算软件,可为现场应用提供参考依据。
[Abstract]:The open window radial horizontal well technology is a typical application of water jet increasing production and is an effective means to develop low porosity and low permeability oil and gas reservoirs. Different from the conventional horizontal wells, hydraulic rock breaking bit is used in the open window horizontal wells to realize rock breaking drilling. The drill string is usually small diameter continuous tubing and high pressure hose, and the flow resistance of drilling fluid in the pipe string is high. A large amount of hydraulic energy is consumed on the side loss, and the water power obtained by the rock breaking bit is limited. If the water power of the bit is increased only by increasing the surface pump pressure, the equipment cost will be greatly increased. Therefore, in this study, the technical idea of adding drag reducing agent to the drilling fluid to reduce the loss along the path is put forward. Based on the analysis of drag reduction mechanism of different types of drag-reducing agents, this study takes the diameter 8mm hose commonly used in the new radial horizontal well technology as the analysis object, and adopts the numerical simulation method. The relationship between pipe length, displacement and viscosity under the condition of clear water and viscoelasticity is systematically studied. It is found that the loss along the pipe under visco-elastic conditions is obviously reduced compared with that of clear water drilling fluid. When the viscosity is 13.5cp, the loss along the tube is the smallest, and the drag reduction rate is the highest (51.4%) when the displacement is 60L / min, which provides the theoretical support for the selection of drag reducer in the ground experiment. Secondly, based on the theoretical analysis and numerical simulation results, four drag reducing agents, polyacrylamide (PAM), polyvinyl oxide (PEO) Gemini viscoelastic quaternary ammonium salt surfactant, extreme pressure lubricant HY-2020, were preliminarily selected. The side loss of 8mm nylon hose with 16mm diameter and diameter 14.6mm continuous tubing is tested and compared with the water drilling fluid under the same working conditions. It is found that the loss along the path is lower than that of the clear water drilling fluid after the addition of four drag reducing agents. When the mass concentration of Gemini viscoelastic quaternary ammonium salt surfactants is 1.5, not only the drag reduction rate can reach 64.49, but also the resistance to shear is strong. Gemini quaternary ammonium surfactant can be used as an ideal drag reducing agent for horizontal wells with open windows. Finally, the optimization design of hydraulic parameters of a new type of radial horizontal well drilling is carried out, and the calculation software of the loss along the track is developed under the condition of this study, which can provide a reference for the field application.
【学位授予单位】：中国石油大学(华东)
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TE243

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